1. Field of the Invention
The present invention relates to a photographic printing apparatus arranged to diffuse light emitted from a light source and irradiate a negative film with the light diffused.
2. Description of the Related Art
In such a photographic printing apparatus for printing an image on photographic paper, a diffuser box accommodated in a case is disposed between a negative film carrier and a light source, and an image to be printed is formed on photographic paper by diffusing light emitted from the light source in the diffuser box, irradiating a negative film with the thus-diffused light, and exposing the photographic paper to the light transmitted through the negative film.
In this kind of diffuser box, the internal diameter of a light diffusing portion is determined in accordance with the size of each kind of negative film and, each time a negative film of different size is to be employed, it is necessary to replace the diffuser box by a different kind of diffuser box which corresponds to the size of the negative film. To cope with such necessity, in a conventional type of apparatus, the case is detachably attached so that the diffuser box together with the case may be replaced when a negative film of different size is t be employed.
In this case, however, it is necessary to prepare a multiplicity of cases for accommodating diffuser boxes of many kinds each having a light diffusing portion of different size.